You mean 180 and it’s because he has a son and learnt that uke wasn’t the one manipulating the situation. It was his dad once again being a horrible evil person. Uke was a victim to his dad just as much as the seme was. He realised it at first when he got told by galilei and then he confirmed it when he had pheromone rejection because he met his fated mate and was far away from him. That’s why he regrets his actions to the point of willingly letting uke leave despite knowing it will hurt him. It makes more sense when you realise it’s been 5 months at least. He has been stewing and changing and regretting for 5 months if not longer. Also this whole time he’s been a tsundere. He felt the same magnetic pull the uke felt but he wanted to stay in denial so he ignored it and treated uke as shit as his feelings for uke ran.
Why'd his personality do a 360??